Luminaire

Abstract: The luminaire has a bar grating (10) in front of the light emission window (4) in order to protect the luminaire against impacts. The bar grating is secured in rubber buffers (20) which are fixed to the housing (1) of the luminaire. The bar grating may be secured by a snap connection (21) along a first side (5) of the window, whereas it is hingeable in buffers (20) along an opposite side (5) thereof.

Description: The invention relates to a luminaire comprising: a housing with a reflector member and means for accommodating an electric lamp therein, which housing has a light emission window; a bar grating connected to the housing and protecting the light emission window. Such a luminaire is known from DE GM 1 918 784. The known luminaire is suitable for illuminating playing areas in sports halls. The bar grating protects the luminaire during use, especially the lamp or lamps and the reflector member, against impacts of balls. Such an impact could destroy the lamps and damage the reflector member, whereby the light-concentrating effect thereof would be lost. The bar grating of the known luminaire is rigidly connected to the housing along the short sides of the rectangular light emission window by means of bolts. When two mutually opposing bolts have been removed, the bar grating can slide over the two remaining mutually opposed bolts accommodated in slotted holes in the grating, after these bolts have been loosened, and can then hinge for the replacement or cleaning of the lamp and the reflector member. It is a disadvantage of the luminaire that the bar grating is comparatively heavy and, partly as a result of this, intercepts comparatively much light. It is an object of the invention to provide a luminaire of the kind described in the opening paragraph with a construction which renders possible the use of a comparatively light bar grating. According to the invention, this object is achieved in that the bar grating is held in rubber buffers which are mounted to the housing. Owing to the measure according to the invention, a substantial portion of the impulse of an impact is absorbed by the buffers. Only a comparatively small portion need be neutralized by a elastic deformation of the bar grating itself. Consequently, the bar grating may be of a lighter construction, for example, comprising bars of 4 mm lateral dimension instead of bars of 6 mm lateral dimension. This leads to a major reduction in the interception of light. An advantage of the luminaire according to the invention also is that the bar grating is mounted rattle-free to the housing. In a favourable embodiment, moreover, the buffers keep the bar grating in position at a distance from the housing. This embodiment has the advantage that there is a greater freedom in the design of the luminaire as regards the number, shape, and dimensions of the buffers in order to realise the desired buffering action in each and every case. The choices may be readily made by those skilled in the art, possibly by means of a single experiment. It is advantageous when the buffers are situated along two mutually opposed sides, for example, in a luminaire with a rectangular light emission window along the long sides thereof. The bar grating may then be evenly supported. The buffers may grip the bar grating in various manners, for example, in that they are kept closed around, for example, a bar of the grating by means of a clip, clamp, or bolt. A very attractive embodiment is that in which the buffers have a snap connection to the bar grating along at least one of the sides of the window, while the buffers along the opposite side hold the bar grating with hinging possibility. The grating may then be pulled from the snap connection at at least one side, for example for cleaning the luminaire, without tools being necessary for detaching it. The grating may then be put in its operational position equally quickly. The snap connection may cooperate, for example, with a bar of the grating and grip around it. The bar may have various cross-sectional shapes, for example, flat, polygonal or, very conveniently, round. In a favourable modification which is logistically attractive, the buffers are all of one and the same kind. It is possible then for the buffers to have a snap connection to the bar grating while the grating is at the same time hingeable in these buffers. It is advantageous when the reflector member has slats extending transversely thereto. The possibility of looking directly into a accommodated lamp can be avoided by this. When a bar grating with longitudinal bars and transverse bars fastened thereto is used, it is favourable when the transverse bars are in one line each time with a slat of the reflector member, as seen in a direction perpendicular to the light emission window. The interception of light by the bar grating is further minimized by this. In another favourable embodiment, the reflector is shaped for forming a asymmetrical beam from the light generated by a accommodated electric lamp. This embodiment has the advantage that the luminaire may be suspended next to instead of above a playing area, for example a tennis court, and nevertheless illuminates this area evenly without the luminaire in its entirety having to be mounted with its light emission window at an angle to the floor of the playing area. Positioning next to the playing area has the advantage that the possibility of looking into the luminaire is further reduced, that the full height of the hall above the playing area remains available, and that the luminaire may be mounted at a lower level, if so desired. The luminaire then provides a brighter illumination, or may be provided with a lamp of lower power. The buffers may be mounted to the housing in various ways, for example, in that they are forced with a locally widened portion through a opening in the housing and hook behind the housing with this widened portion. An embodiment of the luminaire according to the invention is shown in the drawing, in which Fig. 1 is a longitudinal sectional view of the luminaire; and Fig. 2 is a cross-section taken on the line II-II in Fig. 1 with a lamp. The luminaire comprises a housing 1 with a reflector member 2 and means 3 for accommodating an electric lamp 9, a tubular fluorescent lamp in Fig. 2. The housing 1 has a light emission window 4. A bar grating 10 is connected to the housing 1. It protects the light emission window 4. The luminaire drawn is suitable for accommodating two of the said lamps, for example, each of 36 W or 58 W. The reflector member accordingly is constructed as a dual reflector member. The bar grating 10 is held in rubber buffers 20 which are fastened to the housing 1. In the embodiment shown, they are pressed with a widened portion 22 through an opening 7 in the housing 1 and hook behind the housing with this widened portion. In the embodiment shown, the buffers 20 keep the bar grating in position at a distance from the housing 1. The buffers 20 are present along two mutually opposing sides 5 of the light emission window 4. The light emission window shown is rectangular and the buffers 20 are arranged along the long sides 5, which are approximately 1.20 m and approximately 1.50 m long in the case of 36 W and 58 W lamps, respectively. The buffers along the one side are identical to those along the other side. The buffers 20 have a snap connection 21 to the bar grating 10 along at least one of the said sides 5. The buffers along the other one of these sides 5 hold the bar grating 10 in hinging fashion. Since the buffers shown are identical, they each have a snap connection to the bar grating, while this grating is at the same time hingeable in each buffer. The reflector member 2 has slats 6 which extend transversely thereto. The bar grating 10 has longitudinal bars 11 and transverse bars 12 fastened thereto, the transverse bars 12 lying in front of the light emission window 4 in line with slats 6 of the reflector member 2, as seen in a direction perpendicular to the window. The reflector member 2 is shaped for forming a asymmetrical beam from the light generated by a accommodated electric lamp. A ray b 1 is reflected as ray b 2 in a same direction as a ray a 2 which was formed after two reflections of a ray a 1 emitted by the lamp and forming the mirrored image of the former ray b 1 . The bar grating shown halves the light losses in the radiated light beam which are a result of a conventional bar grating with bars of 6 mm diameter in the light emission window, thanks to its bars of 4 mm diameter. Nevertheless, the grating offers the luminaire an excellent protection against impacts such as, for example, those caused by balls when the luminaire is used for lighting a playing area in a sports hall. Owing to the asymmetrical beam, the luminaire can be suspended laterally of such a playing area.

Claims: A luminaire comprising: a housing (1) with a reflector member (2) and means (3) for accommodating an electric lamp therein, which housing (1) has a light emission window (4); a bar grating (10) connected to the housing (1) and protecting the light emission window (4), characterized in that the bar grating (10) is held in rubber buffers (20) which are mounted to the housing (1). A luminaire as claimed in Claim 1, characterized in that the buffers (20) keep the bar grating in position at a distance from the housing (1). A luminaire as claimed in Claim 1 or 2, characterized in that the buffers (20) are situated along two mutually opposed sides (5) of the light emission window (4). A luminaire as claimed in Claim 3, characterized in that the buffers (20) are present along the long sides (5) of a rectangular light emission window (4). A luminaire as claimed in Claim 3 or 4, characterized in that the buffers (20) have a snap connection (21) to the bar grating (10) along at least one of said sides (5), while the buffers along the other one of the sides (5) hold the bar grating (10) with hinging possibility. A luminaire as claimed in Claim 1, 2 or 3, characterized in that the reflector member (2) has slats (6) extending transversely thereto. A luminaire as claimed in Claim 6, characterized in that the bar grating (10) has longitudinal bars (11) and transverse bars (12) fastened thereto, and the transverse bars (12) lie in front of the light emission window (4) in line with slats (6) of the reflector member (2) as seen in a direction perpendicular to the window. A luminaire as claimed in any one of the preceding Claims, characterized in that the reflector member (2) is shaped for forming an asymmetrical beam from the light generated by an accommodated electric lamp (9).

Inventors: PAULY KARSTEN, PAULY, KARSTEN
Applicants: PHILIPS ELECTRONICS NV, PHILIPS PATENTVERWALTUNG, PHILIPS ELECTRONICS N.V., PHILIPS PATENTVERWALTUNG GMBH
Application year: 1994
Main classification: F21V15
IPC codes: F21V15